try:
    print ('try...')
    r=10/0
    print('result:',r)
except ZeroDivisionError as e:
    print ('except:',e)
finally:
    print ('finally...')
print ('END')
try:
    print('try...')
    r = 10 / int('a')
    print('result:', r)
except ValueError as e:
    print('ValueError:', e)
except ZeroDivisionError as e:
    print('ZeroDivisionError:', e)
finally:
    print('finally...')
print('END')
#python 的错误也是class，所有的错误类型都继承自BaseException
